
package com.shai.wool.sensitiveword;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

import com.shai.wool.common.SpringBeansTool;
import com.shai.wool.sensitiveword.entity.SensitiveWordVO;
import com.shai.wool.sensitiveword.param.SensitiveWordParam;
import com.shai.wool.sensitiveword.service.SensitiveWordService;

/**
 * 敏感词检测
 *
 * @author 朱国军
 * @since 1.0
 * @version 2016年5月7日 朱国军
 */
@Component
@Scope("singleton")
public class SensitiveWordUtils {
    
    private static Map<Object, Object> sensitiveWordMap = new HashMap<Object, Object>();
    
    /** 最小匹配规则 */
    private static int minMatchTYpe = 1;
    
    /**
     * 初始化敏感词
     */
    public static void initSensitiveWord() {
        SensitiveWordService sensitiveWordService = SpringBeansTool.context.getBean(SensitiveWordService.class);
        SensitiveWordParam param = new SensitiveWordParam();
        param.setPageSize(Integer.MAX_VALUE);
        param.setPageNo(1);
        List<SensitiveWordVO> sensitiveWordList = sensitiveWordService.queryByPage(param);
        if (sensitiveWordList != null) {
            addSensitiveWordToHashMap(sensitiveWordList);
        } else {
            sensitiveWordMap = new HashMap<Object, Object>();
        }
    }
    
    @SuppressWarnings("unchecked")
    private static void addSensitiveWordToHashMap(List<SensitiveWordVO> keyWordList) {
        sensitiveWordMap = new HashMap<Object, Object>(keyWordList.size()); // 初始化敏感词容器，减少扩容操作
        Map<Object, Object> nowMap = null;
        Map<Object, Object> newWorMap = null;
        // 迭代keyWordSet
        for (SensitiveWordVO sensitiveWord : keyWordList) {
            String key = sensitiveWord.getSensitiveWord(); // 关键字
            nowMap = sensitiveWordMap;
            for (int i = 0; i < key.length(); i++) {
                char keyChar = key.charAt(i); // 转换成char型
                Object wordMap = nowMap.get(keyChar); // 获取
                
                if (wordMap != null) { // 如果存在该key，直接赋值
                    nowMap = (Map<Object, Object>) wordMap;
                } else { // 不存在则，则构建一个map，同时将isEnd设置为0，因为他不是最后一个
                    newWorMap = new HashMap<Object, Object>();
                    newWorMap.put("isEnd", "0"); // 不是最后一个
                    nowMap.put(keyChar, newWorMap);
                    nowMap = newWorMap;
                }
                
                if (i == key.length() - 1) {
                    nowMap.put("isEnd", "1"); // 最后一个
                }
            }
        }
    }
    
    /**
     * 判断文字是否包含敏感字符
     *
     * @param txt 文字
     * @param matchType 匹配规则&nbsp;1：最小匹配规则，2：最大匹配规则
     * @return 若包含返回true，否则返回false
     */
    public static boolean isContaintSensitiveWord(String txt, int matchType) {
        boolean flag = false;
        for (int i = 0; i < txt.length(); i++) {
            int matchFlag = checkSensitiveWord(txt, i, matchType); // 判断是否包含敏感字符
            if (matchFlag > 0) { // 大于0存在，返回true
                flag = true;
            }
        }
        return flag;
    }
    
    /**
     * 获取文字中的敏感词
     *
     * @param txt 文字
     * @param matchType 匹配规则&nbsp;1：最小匹配规则，2：最大匹配规则
     * @return
     */
    public static Set<String> getSensitiveWord(String txt, int matchType) {
        Set<String> sensitiveWordList = new HashSet<String>();
        
        for (int i = 0; i < txt.length(); i++) {
            int length = checkSensitiveWord(txt, i, matchType); // 判断是否包含敏感字符
            if (length > 0) { // 存在,加入list中
                sensitiveWordList.add(txt.substring(i, i + length));
                i = i + length - 1; // 减1的原因，是因为for会自增
            }
        }
        
        return sensitiveWordList;
    }

    /**
     * 替换敏感字字符
     *
     * @param txt 文字
     * @param matchType 匹配规则&nbsp;1：最小匹配规则，2：最大匹配规则
     * @param replaceChar 替换字符，默认'*'
     * @return
     */
    public static String replaceSensitiveWord(String txt, int matchType, String replaceChar) {
        String resultTxt = txt;
        Set<String> set = getSensitiveWord(txt, matchType); // 获取所有的敏感词
        Iterator<String> iterator = set.iterator();
        String word = null;
        String replaceString = null;
        while (iterator.hasNext()) {
            word = iterator.next();
            replaceString = getReplaceChars(replaceChar, word.length());
            resultTxt = resultTxt.replaceAll(word, replaceString);
        }
        
        return resultTxt;
    }
    
    /**
     * 获取替换字符串
     *
     * @param replaceChar 替换字符，默认'*'
     * @param length
     * @return
     */
    private static String getReplaceChars(String replaceChar, int length) {
        String resultReplace = replaceChar;
        for (int i = 1; i < length; i++) {
            resultReplace += replaceChar;
        }
        
        return resultReplace;
    }
    
    /**
     * 检查文字中是否包含敏感字符，检查规则如下：<br>
     *
     * @param txt 文字
     * @param beginIndex
     * @param matchType 匹配规则&nbsp;1：最小匹配规则，2：最大匹配规则
     * @return 如果存在，则返回敏感词字符的长度，不存在返回0
     */
    @SuppressWarnings("unchecked")
    public static int checkSensitiveWord(String txt, int beginIndex, int matchType) {
        boolean flag = false; // 敏感词结束标识位：用于敏感词只有1位的情况
        int matchFlag = 0; // 匹配标识数默认为0
        char word = 0;
        Map<Object, Object> nowMap = sensitiveWordMap;
        for (int i = beginIndex; i < txt.length(); i++) {
            word = txt.charAt(i);
            nowMap = (Map<Object, Object>) nowMap.get(word); // 获取指定key
            if (nowMap != null) { // 存在，则判断是否为最后一个
                matchFlag++; // 找到相应key，匹配标识+1
                if ("1".equals(nowMap.get("isEnd"))) { // 如果为最后一个匹配规则,结束循环，返回匹配标识数
                    flag = true; // 结束标志位为true
                    if (minMatchTYpe == matchType) { // 最小规则，直接返回,最大规则还需继续查找
                        break;
                    }
                }
            } else { // 不存在，直接返回
                break;
            }
        }
        if (matchFlag < 2 || !flag) { // 长度必须大于等于1，为词
            matchFlag = 0;
        }
        return matchFlag;
    }
}
